Friction shock-absorbing mechanism



Feb. s, 1927..

J. F. Q'CONNOR FRICTION SHOCK ABSORBING MECHANISM Filed Feb. 2. 1925 mifi.) 4M J Y ZMM wl Q www 'llVllV @L ,4. Kw1/mn 35% w w 4 W. M Fil/UAJ'OHN F. OCONNOR, OF CHICAGO, ILLISIOIS, 'ASSIGNOR TG VJ. H. MINEB,INC., OIE' CHICAGO, ILLINOIS, A CORPORATION OF, DELAWARE.

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Application filed Fen'ri'iary, 1925., Serial No. 6,225.

pression stroke.

Another object of the invention is to provide a friction shock absorbingmechanism,

Y employing a friction shell'having a pluralitv of friction elementsdirectly cooperate Viiig therewith, resisted by a relatively heavyspring element to absorb the heavier shocks, and a plurality ofadditional friction elements resisted by a relatively light springduring initial action of the mechanism to absorb the lighter shocks.

A further and more specific object of the invention is to provide afriction shock absorbing mechanism, including a friction shell having aplurality of friction shoes cooperating therewith, wherein certain.v ofthe shoes have limited movement relative to the remaining shoes toprovide for prelim-V inary light action and wherein all of the shoes areadapted to move in unison with reference to the shell during theremainder of the compression stroke' to providefheavier final action. Y

Gthei' objects and advantages of the invention will more clearly andfully appear from the description and claims hereinafter following.

ln the specification, Figure l is a longitudinal, horizontal, sectionalview of a portion of a railway draft rigging, showing my` improvementsin connection therewith, the section through the friction elementscorresponding to two section planes 120O apart. Figure 2 is a front endelevational view partly broken away of the shock absorbing mechanism:

proper, and Figure 8 is a transverse, vertical, sectional viewcorresponding` substantially to the line 53m-S of Figure 1.

ln said drawings, 10 10 indicates channel-shaped center or draft sillsof a railway ,Y

car underframe, to the inner faces of which are secured front stop lugs11-11 and rear stop lugs 12-12 drawbar is indicated at 13, to which isoperatively secured a yoke 11iof well-known construction.V lVithin theyoke-are disposed drawing forming a part of `this reference to the cage.

The inner end of thethe usual front `follower 15 and the `shockabsorbing mechanism proper, hereinafter 'more fully described. The yokeand parts contained therewithin are supported in operative position by adetachable saddle plate 16,

My improved shock absorbing mechanism proper, as shown, comprisesbroadly, a spring cage casting A, a friction shell B; a set of outerfriction shoes C,`C,'l); a set of inner friction wedge shoes E, E and F;a main wedge G; twin arranged main springresistance elements lef-ii; amain spring follower J an auxiliary spring resistance K; an

auxiliary spring follower L; and a retainer,

boit M.

rectangular box-likeform having a `transverse end 'wall 17 adapted toco-operate therefrom to provide slots therebetween,

extending from the top to-the `bottom of the spring cage;

The friction shell Bis of generallycylin- Vdrical form and has a pair oflaterally projecting flanges'21-'21fat the rear end there# of adapted tobe inserted in the slots 20 of the spring cage tov retain the shell inassembled relation with the latter and prevent longitudinal vmovementthereof lwith TheN interior of lthe shell B is provided with a seriesofindependent, cylindricaly friction surfaces 23-23, the same beingconverged inwardly of the shell and so disposed that the inneren'ds forma complete, true circle as clearly indicated in Figure 3. As clearlyindicated in Figure 1, the rear endof the friction shell extends beyondthe ianges 21 thereof a distance at least equal to the thickness of therespective ribs 18. f

The three friction shoes C, C and D are of like construction, except ashereinafter pointed out. Each shoe is formed with an outer, truecylindrical friction surface 123 adaptedrto co-operate with therespective shell friction surfaces 23 andan inner, true zo i,

iio

" outer shoe.

cylindrical friction surface 2e adapted to cooperate with one of thefriction shoes of the inner set. At the forward end, each shoe isprovidedk with a relatively short inner beveled face 25 for conveniencein construetion. As clearly shown in `Figure 1, the beveled faces 25 ofthe shoes C, C and D terminate short of the outer sides` of the shoes,thereby providing flat abutment surfaces 26 at the forward ends of saidshoes adapted to engage shoes E, E and F. At the rear end, each of theshoes C, C and D is provided with a lateral fiangei27 adapted tocooperate with an annular shoulder 28 on the inner side of the frictionsli-el to positively limit the outward movement of the shoe.

Three friction wedge shoes E, E and F are also of like construction,except as hereinafter pointed out. Each wedge shoe is formed with anouter, true cylindrical friction surface 12e adapted to cooperate withthe friction surface 2d of the corresponding it the outer end, each shoeis provided with a wedge face 128 on the inner side thereof. rlhe faces128 of the two shoes ,E extend at relatively blunt angle with respect tothe longitudinal axis of the mechanism and the faces 128 of the shoe l?extends at a relatively heen angle to said axis. is clearly shown inFigure 1, the wedge shoes E, E and F have their forward ends projecting`outwardly beyond the shoes C, C and D and have portions thereof extendedlaterally as indicated at 29, the projecting portions 29 beinglongitudinally alined with the respective shoes C, C and D and spacedtherefrom. @n the inner side of the project-ing portion, each wedge shoehas a beveled face 125 ycorrespondingly inclined to the beveled face 25ofthe corresponding friction shoe of the outer set. Each of the shoes E,E and F is also provided with a transverse abutment face 126 adapted tocooperate with the abutment faces 26 of the corresponding shoe of theouter set to limit relative movement of the shoes of the inner and outerset after a predetermined compression of the mechanism. ln thisconnection, it is pointed out that the shoes C, C, D, E, E and l? arepreferably all made of cast steel and that the shell is preferably madeof malleable iron. 1With such an arrangement, it will be evident that itis not absolutely essential that the shoes C, C and D be provided withmeans for limiting their outward movement, such as the lugs 27. Due tothe relatively higher friotionalvresistance between malleable iron andsteel than between steel and steel, the inner Leiaele shell and bereturned to release engagement with follower tl.

The wedge G is preferably iin the form of a cast block having a flatfront face 30 adapted to bear directly against the front follower 15.Ait the inner end the block Gr is provided with three rearwardlyconi/'erging wedge faces 228-228 arranged around the axis of themechanism. 'lwoof the faces 228 coact with the faces 128 of the twoblunt shoes E and are correspondingly inclined, and the remaining` wedgeface 228 is inclined to correspond with the wedge face 128 of the shoe Fand is adapted to cooperate therewith. p

The spring follower J is in the form of a position by generallyrectangular plate having a forwardly projecting annular flange 31Y atthe front side thereof, adapted tov extend into and work within the rearend of the shell B as clearly illustrated iin Figure 1.` The annularflange 31V is adapted to abut the rear ends of the shoes C, C and D andfunctions as a pressure-transmitting member to transmit the actuatingforce from the shoes C, C and D to the main spring resistance elementsH. The annular flange 31 also has another function, namely, that ofmaint-aining the friction shell in assembled relation with the springcage, the flange 31 preventing vertical movement of the shell Vwhen theflange is disposed within the rear end of the y latter. Outward movementof the spring follower J is limited by the opposite sides thereof whichnormally bear on the inner sides of the recess 18' ofthe cage A. Y

The twin arranged spring resistance elements ll are disposed within thevspring cage and have their opposite ends bearing respectively on themain spring follower and the end wall 1T of the cage. Each member of thetwin spring resistance elements preferably consists of an inner,relatively light Vcoil and a heavier, outer coil as clearly shown inlligure 1.. The auxiliary spring resistance K which also preferablyconsists of a ylight inner coil and a relatively heavier outer coil isinterposed between the auxiliary spring follower L and the main springfollower il, the rear end of the spring resistance l being seated withinthe annular flange 31 on the main spring follower. The s aring followerL bears directly on the inner ends of the friction wedge shoes E, E andF. The parts are held under initial compression and of overall, uniformlength by the retainer bolt M, which has its opposite ends anchored tothe main follower and wedge G respectively, the innerl end of the boltbeing threaded into a boss 32 lon the main spring follower and the headof the bolt at the opposite end thereof being accommodated in a recesswithin the wedge block G.

Assuming` a compression stroke of the mechanism, the operation is asfollows: The

ico

lill) Vwardly on the friction surfaces of the slices C, C and D,compressing kthe auxiliary spring vagainst the main spring follower J,the latter during this stage of the-opera- Y tion being retained in itsoutermost position by the main springsV t-l. The Vmain springs arepreferably under considerable initial compression so vthat there willbev sub` stantiallyno movement of the sp 1ing follower J during theaction just` described. The relative movement of the shoes con tinuesuntil the faces 25 and 125 and the shoulders 26 and V126 thereof comeinto abutment, whereupon the shoes C, C and l) will `be carried inwardlyin unison with the shoes E, E and F. There will be no furthercoinpression of the auxiliary spring resistance during the remainder ofthe compression stroke, inasmuch asV the relative movement of the shoesis positively arrested at the vend of the preliminary action justdescribed. During the remainder of the compression stroke, the shoesC,C' and D will be forced to slide on the friction surfaces of 'the shell,

B, the inward movement of the shoes being resisted by the twinvarrangedmain spring resistance elements, the pressure being transymitted fromthe former to the latter directly through the main spring follower J,which has the flange 8l thereof in abutment with ldie inner ends of theshoes C and D. action will continue until the actuating force isreduced, or until the main follower comes into engagement with the outerend ofthe friction shell, whereby the pressure will be vrJ-nsniitteddirectly through the shell and spring cage to the corresponding stopings.

During this latter part of the travel, there will be differential actionbetween shoes and wedge Gdue to taper ofwalls of the friction shell.

Due to the employmentof the blunt and heen sets of wedge faces, l amenabled 'to obtain a very high wedgino action duringY the compressionstroke, since the' wedge "faces may be mace relatively acute withoutdanger ,of the parts sticking, the blunt wedge faces acting more or lessas safety valves to prevent sticking. In this connection, it will beunderstood by those skilled in the art that my improvements are capableof use in a mechanism either employing a blunt and keen angle system,orwedgek faces which are and the wedge shoes This' tional engagement Vwitheach other all of the same angle with yrespect to the axis of lthemechanism. derstood that Vthe co-acting friction surfaces of the innerand outer sets of Vfriction shoes maybe arranged to convergeinw-ardly'of It will Valso be un-` the mhani-sm instead of beingdisposed f parallel to the aXis of the same.

ln release, the inain andauxiliary springs effectively restore all theparte to vnormal y position, the lugs 2l on the shoes C, C and l)limiting the outward movement thereof to-properly space the saniewithreference to the shoulders on the inner set of shoes. When the mechanismis in full release, outvward movement of the wedge-G and c0- actingparts will be limited by the retainer bolt lvl. It will also beevidentthat the annular flange Sl'on the main 'spring follower tlf-serves topositively force vthe slices C and D to theirfuli release position.A p YThe preliinii'iary'action provided in my improved shockabsorbingmechanism, as hereinbefore described, particularly adapts thesame for usecin connection with passenger cars.

llihile Vl have herein shown .and described invention, the same ismerely illustrative and l contemplate all changes'and modifications thatcome within vthe scope of the claims appended hereto.

l cla-im: i Y l fl. ln a friction shock absorbingmechanism', thecombination witha friction shell provided with friction surfaces;friction shoes cooperating with the shell friction sun face-s; aA mainspring resistanceelement opposing relative movement of said shoes andshe-ll; wedge shoes lia-ving frictional engagement with said first namedshoes, and

having limited relative movement thereto;

"the'preferred manner of carryingfo'ut my l Uitl a preliminary springresistance opposing relative movement of said first andsec-ond named'`shoes during the limited relative movement thereof; and ywedge-presseretransmitting means co-operating withV the wedge shoes, only for forcingthe same outwardly against said friction shoes to press the latteraeainst said shell friction surfaces.

Y 2. In' a friction shock absorbing mecha.-

-nism, the combination with a friction shell;

two Vsets of friction shoes, said sets being relatively movable withreference to each other to a limited extent and having'fiicand one onlyof said setshaving frictional engage nient with'the shell; armain springresist- `ance element opposing movement of one set of shoes; apreliminary spring resistance element opposing relative moven'ient ofthe sie two sets of shoes during the limitedvmovei ment thereof; and`wedgepressure-transmitting means for forcing said -setsof shoes intointimate frictional-contact and ,forcing the sets of shoes havingfrictional engagement with the shell into intimate contact with thelatter. Y Y

3. In a friction shock absorbing mechanism; the combination with acolumn element having friction surfaces; of a plurality of co-operatingfriction shoes having interengaging friction surfaces; certain of saidshoes being movable with reference to the remaining shoes duringpreliminary action of the mechanism; the last named shoes havingfrictional engagement with the friction surfaces of said element; aspring resistance elementopposing relative movement of the frictionelements and the shoes cooperating therewith;'means for limitingrelative movement of said co-operating shoes after a predeterminedcompression of the mechanism; a preliminary spring resistance elementopposing relative movement of said cooperating shoes during saidpreliminary action; and pressure transmitting spreading Vmeansforpressing said shoes having frictional engagement with said elementinto intimate contact therewith. v

'4L-*ln a friction shock absorbing mechanism, the combination with aplurality of relatively movable friction elements; ofpressure-transmitting means for moving said elements relatively to eachother and forcing the same into tight frictional contact; coacting meanson certain of said elements for limiting the relative movement thereofduring compression of the mechanism; a spring resistance opposingrelative movement between the elements having limited relative movement;and a second spring resistance opposing relative movement between saidlast named elements and the remaining elements, said last named springresistance bel ing of'greater capacity than said first named springresistance.

5. In a friction shoclrabsorbing machanism; the combination with afriction shell; of a plurality of'friction shoes cooperating with thefriction shell and movable inwardly thereof during compression of themechanism; additional shoes having frictional engagement with said firstnamed shoes; a spring resistance cooperating with the first named shoes;and an additional spring cooperating with the remaining shoes;interengaging abutment means on said first and second named shoes forarresting relative movement after a predetermined compression of themechanism; and wedge-pressuretransmitting means cooperating with saidsecond named shoes.

6. In a friction shock absorbing mechanism, the combination with afriction shell; of a plurality of friction shoes cooperating with thefriction shell and movable inwardly vthereof during compression of themechanism'; additional shoes having frictional engagement with saidfirst named shoes; a

spring resistance cooperating with the first named shoes; an additionalspring cooperating with the remaining shoes; wedgeY faces on said firstand second named shoes,rsaid faces being normally spaced apart to permita predetermined amount of preliminary action and adapted to interengageto effect movement of said first named shoes in unison with said secondnamed shoes after full compression of the additional spring resistance;and wedge-pressure-transmitting means cooperating with said second namedshoes.

7. In a friction shock absorbing mechanism, the combination with afriction shell; of a plurality of friction shoes cooperating with thefriction shell and movable inwardly thereof during compression of themechanism additional shoes having frictional engagement with said firstnamed shoes; a spring resistance cooperating with the first named shoes;and an additional spring cooperating with the remaining shoes; a springfollower interposed between said spring resistance elements; said springfollower also engaging said first named shoes; means operativeV after apredetermined relative movement of said first and second named shoes forcausing all of said shoes to move in unison inwardly of the mechanismduring the remainder of the compression stroke; andwedge-pressure-transmitting means cooperating with said second'namedshoes.

8. In a friction shoclr absorbing mechanism; the combination with afriction shell; of friction shoes cooperating with the shell; a mainspring resisting movement of said shoes inwardly of the shell;wedge-shoes having frictionalengagement with said first named shoes; anadditional spring resisting relative movement of said first and secondlnamed shoes; and wedge-pressure transmitting means having wedge facescooperating with said wedge faces of the second named shoes, said meansand certain of said shoes having the cooperating faces disposed at arelatively blunt releasing angle with reference to the longitudinal axisof the mechanism, and the remaining cooperating faces of said means andwedge shoes being disposed at relatively lkeen wedge-acting angles withreference to said aXis.

9. In a friction shock absorbing mechanism, the combination with afriction shell; a friction wedge system co-acting withthe shell, saidsystem including a plurality of friction-shoes, and wedge means forspreading said slices, said shoes having limited relative movement; amain spring resistance; pressure-transmitting means; anda preliminaryspring resista-nce operative-ly interposed between certain of said shoesand the pressure transmitting means, said pressure transmitting meansdirectly co-acting with the remaining shoes to transmit the actuatingforce directly therefrom` to the main spring resistance after thepreliminary leo spring has been compressed to a predetermined eXtent. Yi

10. In a friction shock absorbing mechanism, the combination with afriction member having friction surfaces; of Va set of friction elementsdirectly cooperable with said friction surfaces; a second Yset offriction elements having frictional engagement onl)T with said firstnamed set of friction elements and adapted for limited vmovement withrespect thereto during* the initial portion of a compression stroke;Wedfre-pressure transmitting means cooperable with said second named setof friction elements.; and spring means for initially resisting relativemovement between said first named set of rfriction elements and frictionmember While relative movement is taking place between said first andsecond named" sets of friction elements and for thereafter yieldinglyre# sisting relative movement between said friction member and saidfriction elements.

In Witnessthat I claim the foregoing I have hereunto subscribed mynaine'this 31st day of January 1925.

JOHN F. OCONNOR.

